API java : X509CRL

java.security.cert
Class X509CRL

java.lang.Object
  java.security.cert.CRL
      java.security.cert.X509CRL

All Implemented Interfaces:

X509Extension

public abstract class X509CRL
extends CRL
implements X509Extension

Abstract class for an X.509 Certificate Revocation List (CRL). A CRL is a time-stamped list identifying revoked certificates. It is signed by a Certificate Authority (CA) and made freely available in a public repository.

Each revoked certificate is identified in a CRL by its certificate serial number. When a certificate-using system uses a certificate (e.g., for verifying a remote user's digital signature), that system not only checks the certificate signature and validity but also acquires a suitably- recent CRL and checks that the certificate serial number is not on that CRL. The meaning of "suitably-recent" may vary with local policy, but it usually means the most recently-issued CRL. A CA issues a new CRL on a regular periodic basis (e.g., hourly, daily, or weekly). Entries are added to CRLs as revocations occur, and an entry may be removed when the certificate expiration date is reached.

The X.509 v2 CRL format is described below in ASN.1:

CertificateList  ::=  SEQUENCE  {
     tbsCertList          TBSCertList,
     signatureAlgorithm   AlgorithmIdentifier,
     signature            BIT STRING  }

More information can be found in RFC 2459, "Internet X.509 Public Key Infrastructure Certificate and CRL Profile" at http://www.ietf.org/rfc/rfc2459.txt .

The ASN.1 definition of tbsCertList is:

TBSCertList  ::=  SEQUENCE  {
     version                 Version OPTIONAL,
                             -- if present, must be v2
     signature               AlgorithmIdentifier,
     issuer                  Name,
     thisUpdate              ChoiceOfTime,
     nextUpdate              ChoiceOfTime OPTIONAL,
     revokedCertificates     SEQUENCE OF SEQUENCE  {
         userCertificate         CertificateSerialNumber,
         revocationDate          ChoiceOfTime,
         crlEntryExtensions      Extensions OPTIONAL
                                 -- if present, must be v2
         }  OPTIONAL,
     crlExtensions           [0]  EXPLICIT Extensions OPTIONAL
                                  -- if present, must be v2
     }

CRLs are instantiated using a certificate factory. The following is an example of how to instantiate an X.509 CRL:

<code> 
 InputStream inStream = new FileInputStream("fileName-of-crl");
 CertificateFactory cf = CertificateFactory.getInstance("X.509");
 X509CRL crl = (X509CRL)cf.generateCRL(inStream);
 inStream.close();
 </code>

See Also:

CRL, CertificateFactory, X509Extension

Constructor Summary
protected	X509CRL()           Constructor for X.509 CRLs.

 

Method Summary
boolean	equals(Object other)           Compares this CRL for equality with the given object.
abstract  byte[]	getEncoded()           Returns the ASN.1 DER-encoded form of this CRL.
abstract  Principal	getIssuerDN()           Denigrated, replaced by getIssuerX500Principal().
X500Principal	getIssuerX500Principal()           Returns the issuer (issuer distinguished name) value from the CRL as an X500Principal.
abstract  Date	getNextUpdate()           Gets the nextUpdate date from the CRL.
abstract  X509CRLEntry	getRevokedCertificate(BigInteger serialNumber)           Gets the CRL entry, if any, with the given certificate serialNumber.
X509CRLEntry	getRevokedCertificate(X509Certificate certificate)           Get the CRL entry, if any, for the given certificate.
abstract  Set<? extends X509CRLEntry>	getRevokedCertificates()           Gets all the entries from this CRL.
abstract  String	getSigAlgName()           Gets the signature algorithm name for the CRL signature algorithm.
abstract  String	getSigAlgOID()           Gets the signature algorithm OID string from the CRL.
abstract  byte[]	getSigAlgParams()           Gets the DER-encoded signature algorithm parameters from this CRL's signature algorithm.
abstract  byte[]	getSignature()           Gets the signature value (the raw signature bits) from the CRL.
abstract  byte[]	getTBSCertList()           Gets the DER-encoded CRL information, the tbsCertList from this CRL.
abstract  Date	getThisUpdate()           Gets the thisUpdate date from the CRL.
abstract  int	getVersion()           Gets the version (version number) value from the CRL.
int	hashCode()           Returns a hashcode value for this CRL from its encoded form.
abstract  void	verify(PublicKey key)           Verifies that this CRL was signed using the private key that corresponds to the given public key.
abstract  void	verify(PublicKey key, String sigProvider)           Verifies that this CRL was signed using the private key that corresponds to the given public key.

 

Methods inherited from class java.security.cert.CRL
getType, isRevoked, toString

 

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

 

Methods inherited from interface java.security.cert.X509Extension
getCriticalExtensionOIDs, getExtensionValue, getNonCriticalExtensionOIDs, hasUnsupportedCriticalExtension

 

Constructor Detail

X509CRL

protected X509CRL()

Constructor for X.509 CRLs.

equals

public boolean equals(Object other)

Compares this CRL for equality with the given object. If the other object is an instanceof X509CRL, then its encoded form is retrieved and compared with the encoded form of this CRL.

Overrides:

equals in class Object

Parameters:

other - the object to test for equality with this CRL.

Returns:

true iff the encoded forms of the two CRLs match, false otherwise.

See Also:

Object.hashCode(), Hashtable

hashCode

public int hashCode()

Returns a hashcode value for this CRL from its encoded form.

Overrides:

hashCode in class Object

Returns:

the hashcode value.

See Also:

Object.equals(java.lang.Object), Hashtable

getEncoded

public abstract byte[] getEncoded()
                           throws CRLException

Returns the ASN.1 DER-encoded form of this CRL.

Returns:

the encoded form of this certificate

Throws:

CRLException - if an encoding error occurs.

verify

public abstract void verify(PublicKey key)
                     throws CRLException,
                            NoSuchAlgorithmException,
                            InvalidKeyException,
                            NoSuchProviderException,
                            SignatureException

Verifies that this CRL was signed using the private key that corresponds to the given public key.

Parameters:

key - the PublicKey used to carry out the verification.

Throws:

NoSuchAlgorithmException - on unsupported signature algorithms.

InvalidKeyException - on incorrect key.

NoSuchProviderException - if there's no default provider.

SignatureException - on signature errors.

CRLException - on encoding errors.

verify

public abstract void verify(PublicKey key,
                            String sigProvider)
                     throws CRLException,
                            NoSuchAlgorithmException,
                            InvalidKeyException,
                            NoSuchProviderException,
                            SignatureException

Verifies that this CRL was signed using the private key that corresponds to the given public key. This method uses the signature verification engine supplied by the given provider.

Parameters:

key - the PublicKey used to carry out the verification.

sigProvider - the name of the signature provider.

Throws:

NoSuchAlgorithmException - on unsupported signature algorithms.

InvalidKeyException - on incorrect key.

NoSuchProviderException - on incorrect provider.

SignatureException - on signature errors.

CRLException - on encoding errors.

getVersion

public abstract int getVersion()

Gets the version (version number) value from the CRL. The ASN.1 definition for this is:

version    Version OPTIONAL,
             -- if present, must be v2<p>
 Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
             -- v3 does not apply to CRLs but appears for consistency
             -- with definition of Version for certs

Returns:

the version number, i.e. 1 or 2.

getIssuerDN

public abstract Principal getIssuerDN()

Denigrated, replaced by getIssuerX500Principal(). This method returns the issuer as an implementation specific Principal object, which should not be relied upon by portable code.

Gets the issuer (issuer distinguished name) value from the CRL. The issuer name identifies the entity that signed (and issued) the CRL.

The issuer name field contains an X.500 distinguished name (DN). The ASN.1 definition for this is:

issuer    Name
 
 Name ::= CHOICE { RDNSequence }
 RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
 RelativeDistinguishedName ::=
     SET OF AttributeValueAssertion
 
 AttributeValueAssertion ::= SEQUENCE {
                               AttributeType,
                               AttributeValue }
 AttributeType ::= OBJECT IDENTIFIER
 AttributeValue ::= ANY

The Name describes a hierarchical name composed of attributes, such as country name, and corresponding values, such as US. The type of the AttributeValue component is determined by the AttributeType; in general it will be a directoryString. A directoryString is usually one of PrintableString, TeletexString or UniversalString.

Returns:

a Principal whose name is the issuer distinguished name.

getIssuerX500Principal

public X500Principal getIssuerX500Principal()

Returns the issuer (issuer distinguished name) value from the CRL as an X500Principal.

It is recommended that subclasses override this method.

Returns:

an X500Principal representing the issuer distinguished name

Since:

1.4

getThisUpdate

public abstract Date getThisUpdate()

Gets the thisUpdate date from the CRL. The ASN.1 definition for this is:

thisUpdate   ChoiceOfTime
 ChoiceOfTime ::= CHOICE {
     utcTime        UTCTime,
     generalTime    GeneralizedTime }

Returns:

the thisUpdate date from the CRL.

getNextUpdate

public abstract Date getNextUpdate()

Gets the nextUpdate date from the CRL.

Returns:

the nextUpdate date from the CRL, or null if not present.

getRevokedCertificate

public abstract X509CRLEntry getRevokedCertificate(BigInteger serialNumber)

Gets the CRL entry, if any, with the given certificate serialNumber.

Parameters:

serialNumber - the serial number of the certificate for which a CRL entry is to be looked up

Returns:

the entry with the given serial number, or null if no such entry exists in this CRL.

See Also:

X509CRLEntry

getRevokedCertificate

public X509CRLEntry getRevokedCertificate(X509Certificate certificate)

Get the CRL entry, if any, for the given certificate.

This method can be used to lookup CRL entries in indirect CRLs, that means CRLs that contain entries from issuers other than the CRL issuer. The default implementation will only return entries for certificates issued by the CRL issuer. Subclasses that wish to support indirect CRLs should override this method.

Parameters:

certificate - the certificate for which a CRL entry is to be looked up

Returns:

the entry for the given certificate, or null if no such entry exists in this CRL.

Throws:

NullPointerException - if certificate is null

Since:

1.5

getRevokedCertificates

public abstract Set<? extends X509CRLEntry> getRevokedCertificates()

Gets all the entries from this CRL. This returns a Set of X509CRLEntry objects.

Returns:

all the entries or null if there are none present.

See Also:

X509CRLEntry

getTBSCertList

public abstract byte[] getTBSCertList()
                               throws CRLException

Gets the DER-encoded CRL information, the tbsCertList from this CRL. This can be used to verify the signature independently.

Returns:

the DER-encoded CRL information.

Throws:

CRLException - if an encoding error occurs.

getSignature

public abstract byte[] getSignature()

Gets the signature value (the raw signature bits) from the CRL. The ASN.1 definition for this is:

signature     BIT STRING

Returns:

the signature.

getSigAlgName

public abstract String getSigAlgName()

Gets the signature algorithm name for the CRL signature algorithm. An example is the string "SHA-1/DSA". The ASN.1 definition for this is:

signatureAlgorithm   AlgorithmIdentifier<p>
 AlgorithmIdentifier  ::=  SEQUENCE  {
     algorithm               OBJECT IDENTIFIER,
     parameters              ANY DEFINED BY algorithm OPTIONAL  }
                             -- contains a value of the type
                             -- registered for use with the
                             -- algorithm object identifier value

The algorithm name is determined from the algorithm OID string.

Returns:

the signature algorithm name.

getSigAlgOID

public abstract String getSigAlgOID()

Gets the signature algorithm OID string from the CRL. An OID is represented by a set of nonnegative whole numbers separated by periods. For example, the string "1.2.840.10040.4.3" identifies the SHA-1 with DSA signature algorithm, as per RFC 2459.

See getSigAlgName for relevant ASN.1 definitions.

Returns:

the signature algorithm OID string.

getSigAlgParams

public abstract byte[] getSigAlgParams()

Gets the DER-encoded signature algorithm parameters from this CRL's signature algorithm. In most cases, the signature algorithm parameters are null; the parameters are usually supplied with the public key. If access to individual parameter values is needed then use AlgorithmParameters and instantiate with the name returned by getSigAlgName.

See getSigAlgName for relevant ASN.1 definitions.

Returns:

the DER-encoded signature algorithm parameters, or null if no parameters are present.